How Much Subwoofer Is Enough?

[Chromatischism]

I find 85dB too loud at home, mostly because movies on DVD/Bluray are mastered too hot. I usually set my volume somewhere between-12 and -8 dB.

I listen at -20, sometimes -25. I'll run a fun blast at -10 but I turn it down right after.

-20 should be 85 dB average
-30 should be 75 dB average

Varies by movie, of course.

The LFE channel is offset by +10.

And this assumes you calibrated your AVR such that 0 MV = 75 dB using a -30 dB test tone (how Audyssey works by default).

Source:

THX reference level explained

What is ‘THX Reference Level’? Reference level is a calibrated volume setting used for both movie production (in dubbing stages and post production houses) and reproduction (in screening rooms and theaters). The human hearing system is non-linear, especially in the bass, so having a consistent...

acousticfrontiers.com

 

[Bugal1998]

I listen at -20, sometimes -25. I'll run a fun blast at -10 but I turn it down right after.

-20 should be 85 dB average
-30 should be 75 dB average

Varies by movie, of course.

The LFE channel is offset by +10.

And this assumes you calibrated your AVR such that 0 MV = 75 dB using a -30 dB test tone (how Audyssey works by default).

Source:

THX reference level explained

What is ‘THX Reference Level’? Reference level is a calibrated volume setting used for both movie production (in dubbing stages and post production houses) and reproduction (in screening rooms and theaters). The human hearing system is non-linear, especially in the bass, so having a consistent...

acousticfrontiers.com

Not sure I followed your post, but calibrating a -30db tone to 75db, means setting your AVR volume level to 0db should result in an average movie playback level of 85db, and setting your AVR to -10db should result in an average level of 75db (assuming the movie is mixed to the relevant standards).

Edit: I interpreted both references to "-20" in your post as your AVR volume setting, but upon rereading I don't think think that was your intent.

 

[Bugal1998]

What ends up happening is that even though there isn't much content down there, what is there demands a lot of power to reproduce. If you don't do so, music and movies both end up sounding a little less impressive.

Agreed! Some people will say it's just random rumbles, etc., but rumbles or not, I miss that low frequency content when it isn't reproduced.

Edit: typo

 

[Fredygump]

I think it has to do with human hearing. Sensitivity to absolute levels of low frequencies is much lower. Interestingly, or ability to discern differences in bass levels (difference between 40, 50, 60 Hz) is high.

I don't know what your point is. Yes, this chart gets thrown around a lot, but what does it mean to you?

THX reference level is 115dB for the subwoofer(s?), and 105dB for the rest of the speakers. This number represents dynamic peaks, not dBa (average). These numbers are enough to achieve the intended audio listening experience, and they reflect the amount of dynamic range the audio has. So if you calibrate your system for a flat response, and your components meet reference level, you will experience the movie as it was intended. The sound track was mastered on a reference system that is calibrated for a flat frequency response, so it is recommended that you set up your system the same way.

So I don't know what this chart means to you. In my mind, it might matter if you were an engineer developing the THX standard, or an audio engineer creating the sound track?

 

[Chromatischism]

I don't know what your point is. Yes, this chart gets thrown around a lot, but what does it mean to you?

THX reference level is 115dB for the subwoofer(s?), and 105dB for the rest of the speakers. This number represents dynamic peaks, not dBa (average). These numbers are enough to achieve the intended audio listening experience, and they reflect the amount of dynamic range the audio has. So if you calibrate your system for a flat response, and your components meet reference level, you will experience the movie as it was intended. The sound track was mastered on a reference system that is calibrated for a flat frequency response, so it is recommended that you set up your system the same way.

So I don't know what this chart means to you. In my mind, it might matter if you were an engineer developing the THX standard, or an audio engineer creating the sound track?

Yes, I knew this would come up. Click my post again as I edited it to add more detail. Jack Sparrow must be rubbing off on me. Side note, we've been watching Pirates for the first time in several years. Playing these pre-immersive movies in Uncompressed PCM then upmixing with Neural:X gives the biggest, most dramatic sound here, appropriate for these movies.

 

[mj30250]

However, I don't experience quite what you describe. I've been in stupidly loud cars and know the kind of bass you're talking about. The kind that rattles your ribcage. But, that could be because I'm running a different overall curve. If I listen to music with what you describe, it doesn't sound balanced. But this does. Subs only in a small room:

View attachment 367578
The integration with the main speakers is seamless.

I have also found that a flat bass response can often result in boominess / too much obvious sub involvement with music. With the new PSA subs, I've left them flat up to the crossover region and am enjoying the sound without feeling the need to attenuate the bass. I don't have an explanation for why they are performing differently than prior subs in this area, but it's nice to not feel compelled to flip between "music" and "HT" presets.

My favorite test is the Blade Runner 2049 opening scene up to the point where he lands the police car at the farm. The whole room gets involved.

At high volumes, this sequence is legitimately uncomfortable in my room. The sensation of pressure building is wild and everything in the house that isn't completely secured is rattling/shaking/clanking/flexing like crazy. I haven't been able to get through it at my normal spirited volume levels. Perhaps I'm not as much of a basshead as I thought. Or maybe I'm just getting old.

 

[Purité Audio]

Have you tried measuring with REW and implementing the suggested filters?
Keith

 

[mj30250]

Have you tried measuring with REW and implementing the suggested filters?
Keith

Measuring, yes. So far I'm pleased with the results after using Audyssey XT32 and haven't played with any additional filters. FR, subs only: